The wavelength response of a Mach-Zehnder intensity modulator plays an important role in the Wavelength Division Multiplexing (WDM) where a single variable or multiple wavelengths may be modulated by a single modulator. The modulator properties relevant to WDM have been investigated. See, V. Poudyal and M. Mezhoudi, xe2x80x9cSimultaneous modulation of multiple optical channels with a single Ti:LiNbO3 Mach-Zehnder modulator in a WDM system,xe2x80x9d ICT ""98 International Conference on Telecommunications, pp. 72-76, 1998, incorporated herein by reference. Similar to WDM, modulator wavelength response plays a key role in Photonic Time Stretch and WDM Sampling techniques currently used for enhancing the performance of Analog-to-Digital Converters (ADC). In these systems, the carrier wavelength is continuously tuned while the modulation is being applied.
Changes in the carrier wavelength shift the modulator bias from the optimum xcfx80/2 bias point and cause a strong increase in the second order distortion. At a certain detuning from the center wavelength, the second order distortion begins to exceed the third order one and therefore, in systems with greater than one octave bandwidth, begins to degrade the Spur Free Dynamic Range (SFDR) of the system. To prevent SFDR degradation due to second order distortion, it is therefore presently necessary to limit the optical bandwidth of the system.
Thus, it would be helpful to be able to extend a modulator response analysis to systems with a chirped carrier. It would also be helpful to be able to provide a technique for second-order distortion suppression that is applicable to all multi-wavelengths systems. Furthermore, it would be helpful to be able to provide a wavelength independent biasing (WEB) technique that allows the optical bandwidth of a system to be extended.